Refrigeration apparatus



'Jan. 3, 1933. c. H. THOMAS 1,892,911

REFR IGERATION APPARATUS Filed Oct. 29. 1928 fiVI ENTOR: CYR/LH TH0M/q5) Patented Jan. 3, 1933 UNITED STATES CYRIL H. THOMAS, OF FLOSSMOOR, ILLINOIS, A SSIGNOR TO ItOYAL ELECTRIC MAI TU- FACTURINGCOMPANY, OF CHICAGO, ILLINOIS, A CORIORATION OF ILLINOIS mnzenn rron APPARATUS Application fileil camber 29, 1928. Serial No. 315,773.

My invention relates in general to Cooling systems and has more particular reference to a means for and method of cooling apparatus employing a circulating medium to cool the heat generating parts. 7

' The cooling medium most commonly employed is fluid which is circulated alternate-' ly through the parts to be cooled and a cooling device. In this manner various power devices and apparatus such as electric transformers, regulators, and the like, the bearings of rotating machinery and numerous other apparatus may be maintained at safe operating temperatures, andalthough to illustrate my invention I have shown it as applied in cooling a transformer, itwill be apparent that my invention may be applied equally Well to any apparatus'employing a circulating cooling medium. 7

The circulation of the cooling fluid may, of course, be accomplished either by the thermo syphon principle or by forcedcirculations' as by means of a circulating means, and it will be apparent that'the temperature of the apparatus to be cooled will be determlned by the temperature of the cooling medium supplied to the apparatus;

An important object of my inventionis to provide cooling means of the class described having improved operating efl iciency whereby apparatus may be maintained at a safe operating temperature at all times and irrespective of the fluctuations intemperature enerated within the apparatus by variations in the load carried thereby, said safe oper;

ating temperature being maintained with a minimum of pumping or other operation of the cooling means.

Another important object of theinvention is to provide in combination with a chamber for cooling the cooling medium of power apparatus through which the medium may normally flow by the thermo syphon principle, normally inoperative means for forcing the circulation of the cooling fluid through the cooling chamber, meansfor operating the forcing means when the heat generated within the apparatus increases above normal, and normally inoperativefmeans for artificially coolingsaid cooling chambenop'erable when the heat generated in the apparatus becomes abnormal, said forcing and cooling means being controlled to operate only when the temperature conditions within the apparatus become abnormal so that the cooling may be accomplished with maximum efficiency.

Numerous other objects and advantages of the invention will be apparent from the following description, which, taken'inconnec tion with the accompanying drawing, discloses a-preferred embodiment of the inven tion. 7

Referring to the drawing:

The single View illustrates a" transformer, a refrigerator, means for circulating acooling medium between the transformer and re,- fr gerator and a diagram of electrical cons nections for controlling the operation of the refrigerator. 1 To illustrate my invention, I have shown on the drawing a transformer having ahou'sing or enclosing tank 11 adapted to contain the core and coils of the transformer and the cooling fluid, 1 A refrigerating unit and means for circulating the cooling medium between the transformer and the refrigerating unit are arranged near the transformer case 11. The cooling medium is drawn from the upper portions of the transformer tank through a pipe 12 to a refrigerating coil 13, whence it is returned to the bottom of the transformer tank through a pipe 14:. A I The return pipe 14 is provided with a mois-j ture sump 15 comprising a chamber, through the upper portions of which the returning cooling medium may pass, whatever moisture may be present settling to the lower portions of the sump, whence it may be drained off through a valve suitably positioned in the walls of the sump. Both the outlet pipe 12 and return pipe 14 are providedwith manually operable valves 16 and receptacles 17 adapted to receive a thermometer or other visual temperature indicating device, so that a close check may be maintained upon the temperature of theincoming and outgoing cooling medium. As the cooling medium in PAIN QFFICEIT the tank 11 is heated by the operationo f the transformer, 'a circulation of the cooling medium by thermo siphon process will take I operated. It is necessary therefore to mainplace between the tank 11 and the refrigerating coil 13 through the outlet and return pipes 12 and 14. In this way the temperature of the heated cooling medium received by the coil 13 through the pipe 12 from the transformertank 11, will be reduced in the refrigerating coils and chilled cooling medium will be returned to the transformer through the pipe 14. V

Every apparatus has a critical temperature above which the apparatus can not be safely tain the temperature of the incoming cooling medium below a minimum temperature which depends upon the critical temperature of the apparatus. Under normal conditions the temperatureof the cooling medium may be sufficiently reduced by its passage through cal operating temperature of the apparatus.

the refrigerating coil 13 to maintain the temperature within the tank 13, below the criti- If, however, the apparatus is subjected to abnormal conditions, such as may be induced by overloading the transformer, the temperature of the apparatus may rise above the critical temperature in spite of the cooling effect of the refrigerating coil 13, and I have provided means operable in connection with the refrigerating coil13 whereby the temperature within the tank 11 may be maintained below the critical temperature of the apparatusfirst by reducing the temperature of the coiling medium introduced to the tank through the pipe 14 by increasing the refrigerating effect in the coil 13, and secondly by increasing the rate of circulation of the cooling medium through the refrigerating coils.

The coils 13 are arranged within'a casing 18 and are closely associated therein with the expansion coils 19 of a refrigerating ma chine, including a pump 20, which forces a refrigerant through theexpansion coils 19. The pump 20 is driven by a prime mover 21 which I have illustrated as an electric motor, driven from any suitable source of electric power. By operating the motor 21 and pump 20 to force refrigerant through the coils 18 and thus reduce the temperature of the refrigerating coils 13, the temperature of the 12 and connected through'a force pump 23. The pump 23isdirectly connected for operation' witha prime mover 24, which is illustrated as an electric motor having operating below the critical temperature.

connections with a source of electrical power. The pipe 12 is provided with a check valve 25, arranged therein between the inlet and exhaust connection for the pump 23, the purpose of this valve being to prevent the pump 23 from creating a closed circulation in the bypass 22 and the operation of the pipe 12 extending between the inlet and outlet of the bypass. In this manner the circulation of the cooling medium may-be forced through the refrigerating coil 13-whenever the temperature within the tank 11 threatens to rise above the c'riticaltemperature of the apparatus in spite of the operation of the motor 21 and the refrigerating pump 20. To control the refrigerating pump and its driving motor 21 andthe circulating pump and its driving motor 24, I have arranged control switches 26 and 27 for connecting the motor 21 to the source of electricalv power and a switch 28 for connecting the motor 24 to the source of electrical power. The switches 28 are operated by a switch operating device '30, the switch 27 being controlled by a. similar switch operating device 29. These operating 1 devices 29 and 30 may be of anyknown type and it is not thought necessary for the pur-' pose of explaining the invention to describe the same in detail. Power for operating the. control devices 29 and 30 is supplied by means oflead wires 35 connecting the devices with any suitable source of electrical power. The control device30 is operatively connected by means of a control circuit'32 with a thermostat 31 arrangedin the upper portions of the transformer tank 11, that is to sayat the point of maximum temperature within the transformer tank, while the control device 29 is operatively connected by an operating circuit 34 witha thermostat 33 arranged in the return pipe 14 at a point adjacent its connection to the transformer tank.

It will be apparent that the control device 29 may be calibrated to operate the switch 27 whenever the temperature of the cooling medium fed to the tank 11 exceeds a desired' minimum, that is to say a minimum which under normal circumstances will besuflicient to maintain the temperature of the apparatus;

tion of the control device 29 closes the switch 27 and starts by the motor 21 and refrigerating pump 20 with the resulting increase in refrigerating effect at the cooling medium 13. The temperature of the cooling medium fed to the tank 11 will thus be reduced to a safe temperature.

It will also be apparent that the control device 30 may becalibrated to operate the switches 26 and 28 whenever the temperature The operawithinth-e upper portions of the tank 11 ap- 7 proaches the critical temperature above which the apparatus can not safely operate. The

' closing of switches 26' and 28 starts the mo} tors 21 and24 in oper ation,which'results in the cooling of the refrigerating coil 13 and the forced circulation of the cooling medium so that the temperature of the cooling medium is reduced to a maximum in order to prevent the apparatus from exceeding its critical temperature.

It will be apparent that the refrigerating apparatus and the means for forcing the circulation of the cooling medium are operated only if and when the temperature of the apparatus rises above the safe operating temperature, and that as long as the temperature of the cooling'medium can be maintained within safe limits by thermo syphon circulation through the refrigerating coil, the auxiliary apparatus remains quiescent, so that the cooling effect is provided with maximum efficiency, that is to say with combination of apparatus of my invention, there is no unnecessary operation of the various associate-d devices, so that the cooling effects are provided at a minimum expense of power.

It is thought that the invention and numerous of its attendant advantages will be apparent from the foregoing description and it will be apparent that numerous changes may be made in the form, construction and arrangement of the various parts without departing from the spirit and scope of the invention or sacrificing any of its attendant advantages, the form hereinbefore described 7 being of a preferred embodiment only.

Having thus described my invention, what 7 I claim as new and desire to secure by Letters Patent is:

1. In combination with a device to be cooled, a cooling medium, means forming a thermo syphon circulating system for the cooling medium, said system having a portion extending in the device to be cooled and having a bypass, normally inoperative means for circulating the cooling medium, said means being arranged in said bypass,normally inoperative means for cooling a portion of the system, means for operating the cooling means when the temperature of the cooling medium' exceeds a predetermined value, and means for operating the circulating means when the temperature in the device exceeds a predetermined maximum.

2. In combination with a device to be cooled, a cooling medium, means forming a thermo syphon circulating system for the cooling medium,- said system having a portion extending in the device to be cooled and having a bypass, normally inoperative means for circulating the coolmg medium, said tion of the system, and means for operating the cooling means and circulating means when the temperatures in remote portions of the system exceed predetermined maximum values.

3. In combination with a device to be scribed my name.

cooled, means forming a thermo-syphon circulating system for a cooling medium, said system having a portion extendin into the device to be cooled and havinga y-pass, a normally inoperative pump associated with said by-pass for circulating the cooling medium, normally inoperative means for cooling aportion of the system, means for operating the cooling means when the temperature of the cooling medium'in the system exceeds a predetermined value and means for operating the pump when the temperature of the device being cooled exceeds a predetermined maximum..

4. In combination with a device to be cooled, means forming a thermo-syphon circulating system for a cooling medium, said system having a portion extending into the device to be cooled and having a by-pass, a normally inoperative pump associated with said by-pass for circulating the cooling medium, a normally inoperative refrigerator associated with a portion of the circulating system, means for operating the refrigerator to absorb heat from the circulating system when the temperature of the cooling medium thereof exceeds a pre-determined value and means for operating the pump when the temperature of the device being cooled exceeds a pre-determined maximum.

5. In combination with a device to be cooled, a thermo-syphon circulating system for a cooling medium, said system'having a portion associated with the device to be cooled and having a by-pass, normally inoperative means associated with said by-pass for circulating the cooling medium in the system, normally inoperative refrigerator means associated with a portion of said circulating system, means for actuating the refrigerator means to absorb heat from the circulating system when the temperature of the cooling medium exceeds a predetermined value and means for operating the circulating means when the temperature in the device exceeds a predetermined maximum.

In witness whereof, I have hereunto sub- OYRIL H. THOMAS. 

